Such disk clutches or disk brakes are known in various design embodiments. For example, they are used as shift elements in automatic transmissions of motor vehicles. When made as a wet-running disk clutch this is arranged as the starting clutch in a motor vehicle transmission or even outside it. Wet-running starting clutches are usually cooled by cooling oil radially on the inside, since due to the rotation of the input or outlet side of the clutch, this cooling oil is driven centrifugally outward, providing a transporting action for the cooling oil heated in the clutch.
In the case of a wet-running multiple-disk brake used as a shift member in a variable-speed automatic transmission, this radial transport of the cooling oil is not possible or only very ineffectively so since, when the brake is engaged a rotating brake component is brought to rest against a static brake component with uptake of energy. Accordingly, such brakes are usually either operated completely immersed in the cooling oil or supplied with cooling oil in a controlled manner by way of a pressure gradient.
A conventional wet-running disk clutch is known from DE 41 36 040 C1 in which the cooling oil is delivered to the clutch disks radially from the inside outward. For this, radial openings are formed in an inner disk carrier in an area under the friction linings of the clutch disks, through which the cooling oil can pass to the latter. To achieve an optimum cooling action relatively many radial openings or bores are provided in the disk carrier, which entails comparatively high production costs and can have an adverse effect on the mechanical stability of the disk carrier.
Furthermore, U.S. Pat. No. 6,202,814 B1 discloses a multiple-disk brake in an automatic transmission in which cooling oil can pass to the disks from the outside inward through an annular channel formed radially above the disk set. This cooling oil delivery takes place under pressure and is controllable by a separate valve. In this disk brake, the one-piece disk carrier, fixed on the housing, has radial bores through which the cooling oil can pass from the annular channel to the disks.
To sufficiently cool the disks, a technical solution, illustrated in FIG. 2, has also become known. In this case an inner disk carrier 1 of a disk clutch is formed as a hub 2 on the radially outer side of which driving teeth 3 for holding the inner disks (not shown here), rotationally fixed, are arranged in the usual manner. Through an axial oil delivery duct 4, a cooling oil can be delivered to the inner disk carrier 1, which then continues on through a plurality of radial bores 5, 6, 7, 8 toward the driving teeth 3 and the clutch disks.
To obtain a particularly effective cooling action and to reduce the number of radial bores while also achieving greater mechanical integrity of the inner disk carrier 1, the bores 5, 6, 7 and 8 are formed more or less radially obliquely in the inner disk carrier 1. However, this is not particularly advantageous in relation to production costs, since these openings 5, 6, 7 and 8 in the inner disk carrier 1 cannot be made by more inexpensive stamping methods.
The purpose of the present invention is to further develop a wet-running disk clutch or disk brake so that a good cooling action is obtained and so that it can be produced more inexpensively than known disk clutches or disk brakes while having comparable cooling properties.